1. Field of the Invention
The present invention concerns a method of activating a station, in particular a telephone, connected to a telecommunication central office. The aim of the invention is to enable generalized remote management of any equipment connected to a telecommunication central office, for simplicity a telephone central office.
2. Description of the Prior Art
In the field of telecommunications, the functions of telephone central offices are well known. Central offices mainly use switching processes to interconnect different parties. Because technology has evolved, the parties are no longer always persons; they can be machines. In this case, the telephones are computers or other equipment units exchanging information, in particular digital data, using a particular protocol. Also, real time transmission as routinely used in the field of telephony has evolved toward off-line communication, using voicemail, electronic mail and, more generally, traffic management systems. Similarly, point-to-point communication on demand has been complemented by dedicated links and/or broadcasting, for example via the Internet. Finally, the technology has evolved from simple communication by wire to optical or radio transmission with time-division and/or frequency-division sharing of channels to increase capacity.
Administering all these equipment units has obliged telecommunication operators to distinguish between two types of information to be transmitted on communication channels. A first type of information relates to messages, i.e. to information that the parties wish to exchange. The other type of information relates to signaling. Signaling relates more directly to the administration of a telecommunication network. In practice signaling messages control PBX or public telephone central offices and choose protocols that messages must conform to at a given time to be exchanged correctly via the available communication channels. For example, in a T2 channel, a user granted access to the entire channel in fact has 30 channels for communicating data messages and a dedicated channel for transmitting signaling messages.
The dedicated transmission channel used for signaling messages has naturally been used by telecommunication plant manufacturers to exchange messages for conditioning equipment installed at different places in a network. The ABC F protocol has been developed for this purpose. The ABC F protocol is derived from the ISDN standard Q931. The ABC F protocol covers the organization of signaling messages and instruction codes in each message. In theory each manufacturer must conform to the protocol. Each manufacturer must therefore respect the syntax of the protocol in signaling messages.
However, experience shows that compliance with the above constraints cannot be assured because manufacturers are so varied and requirements are changing so fast. What is more, although each manufacturer might otherwise comply with the standard, because the equipment is so diverse and the manufacturers have diverse origins one manufacturer may choose an instruction with a syntax to correspond to one action and another manufacturer use an instruction with the same syntax for another action. In practice, not enough instruction codes are available.
Another problem that arises is that of remote management of telephones, or more generally of any equipment connected to a remote central office. In a PBX it is a simple matter, complying with a protocol specific to the PBX (called a proprietary protocol), and using circuits specific to the PBX, to control from any telephone connected directly to the PBX another telephone that is also connected directly to it. However, if another PBX similar to the first one is installed elsewhere, it is currently not possible to control from a station connected to the first PBX any of the stations connected to the second PBX as easily as controlling stations connected to the first PBX.
This would involve using the dedicated signaling channel (and the ABC F protocol, for example) to transmit commands and to attempt to navigate the accompanying inextricable organization. The phenomenon is all the more difficult to master in that a link to the other PBX from a first PBX may use a cascade of public central offices (or private PBX) whose protocols for transmission from one central to another do not necessarily conform to the ABC F standard. The link then requires translation. In many cases, translators lose some of the signaling information sent because it differs from the information that their essential mission is to translate.
This solution is nevertheless adopted because, given the standard, circuits are provided in each PBX and in each telephone to interpret instructions received on the dedicated signaling channel (to the ABC F protocol, for example) and have them executed by the telephone to which they are addressed. The equipment is therefore generalized worldwide, which implies a given type of operation, while the routing of corresponding messages progressively becomes impossible.
The aim of the invention is to overcome this drawback by proposing a virtual service network that is transparent to all transmission protocols used from one central office to another. It is even transparent to a transmission protocol used for links with stations connected directly to a PBX. The principle of the invention is to construct service messages and to send them on a normal data channel. The data channel can be of any type (X25, real time or off-line transmission, microwave or fiber optic, etc.). At the receiving end, an orientation circuit recognizes the nature of the signaling message in the receive message and orients it toward a corresponding action, in particular using circuits already present in the stations.
The invention therefore consists in a method of activating a station connected to a telecommunication central office including generation of an activation instruction followed by execution of the instruction by the station, the method including the following steps:
testing whether the instruction must be executed at a station connected to an originating central office at which the instruction is generated,
if it must be executed at a station connected to another central office, establishing a network path between the originating central office and the other central office,
constituting an activation message including information relating to the path, information relating to the instruction, target information relating to the telephone to be activated and activation information relating to the nature of the activation instruction in the message,
transmitting the activation message in the network to the other central office, and
in the other central office, reconstituting the instruction from the activation message and executing it in the station to be activated.
The invention will be better understood after reading the following description and examining the accompanying drawings which are given by way of non-limiting illustrative example only.